refactor: remove unnecessary theme code

Author: francescarpi

src/layouts/Layout.astro

@@ -109,26 +109,6 @@ const alternates = [
     </script>
 
     <ClientRouter />
-
-    <script is:inline>
-      const getThemePreference = () => {
-        if (typeof localStorage !== 'undefined' && localStorage.getItem('theme')) {
-          return localStorage.getItem('theme')
-        }
-        return window.matchMedia('(prefers-color-scheme: dark)').matches ? 'dark' : 'light'
-      }
-      const isDark = getThemePreference() === 'dark'
-      document.documentElement.classList[isDark ? 'add' : 'remove']('dark')
-      document.documentElement.classList[!isDark ? 'add' : 'remove']('light')
-
-      if (typeof localStorage !== 'undefined') {
-        const observer = new MutationObserver(() => {
-          const isDark = document.documentElement.classList.contains('dark')
-          localStorage.setItem('theme', isDark ? 'dark' : 'light')
-        })
-        observer.observe(document.documentElement, { attributes: true, attributeFilter: ['class'] })
-      }
-    </script>
   </head>
 
   <body